Fix markdown table syntax in README (#3897)

packages/gatsby-remark-images/README.md

@@ -45,18 +45,10 @@ plugins: [
 ## Options
 
 | Name | Default | Description |
+|------|---------|-------------|
 | `maxWidth` | `650` | The `maxWidth` in pixels of the div where the markdown will be displayed. This value is used when deciding what the width of the various responsive thumbnails should be. |
 | `linkImagesToOriginal` | `true` | Add a link to each image to the original image. Sometimes people want to see a full-sized version of an image e.g. to see extra detail on a part of the image and this is a convenient and common pattern for enabling this. Set this option to false to disable this behavior. |
-| `sizeByPixelDensity` | `false` |
-Analyze images' pixel density to make decisions about target image
-size. This is what GitHub is doing when embedding images in
-tickets. This is a useful setting for documentation pages with
-a lot of screenshots. It can have unintended side effects on high
-pixel density artworks.
-
-Example: A screenshot made on a retina screen with a resolution of
-144 (e.g. Macbook) and a width of 100px, will be rendered at 50px.
-|
+| `sizeByPixelDensity` | `false` | Analyze images' pixel density to make decisions about target image size. This is what GitHub is doing when embedding images in tickets. This is a useful setting for documentation pages with a lot of screenshots. It can have unintended side effects on high pixel density artworks.<br/><br/>Example: A screenshot made on a retina screen with a resolution of 144 (e.g. Macbook) and a width of 100px, will be rendered at 50px.|
 | `wrapperStyle` | | Add custom styles to the div wrapping the responsive images. Use the syntax for the style attribute e.g. `margin-bottom:10px; background: red;` |
 | `backgroundColor` | `white` | Set the background color of the image to match the background image of your design |